JP2019041421A - Communication system - Google Patents

Abstract

To open the possibility to extend an SIB size as well as to improve scheduling flexibility.SOLUTION: A user device that communicates with a base station comprises: means for receiving a Master Information Block (MIB) including first information on a Broadcast Channel (BCH); means for determining, on the basis of the first information, a Transport Block Size (TBS) for a System Information Block (SIB) and the number of repetitions of the SIB; and means for receiving the SIB on the basis of the first information. The SIB indicates TBS information for other system information.SELECTED DRAWING: Figure 4

Description

  The present invention relates to mobile communication devices and mobile communication networks, and more particularly, but not exclusively, to mobile communication devices and mobile communication networks that operate in accordance with the Third Generation Partnership Project (3GPP) standard or equivalents or derivatives thereof. The present invention particularly relates to UTRAN Long Term Evolution (LTE) (referred to as Evolved Universal Terrestrial Radio Access Network (E-UTRAN)), including but not limited to LTE Advanced.

  In a mobile (cellular) communication network, a (user) communication device (user equipment (UE), also known as a mobile phone) communicates with a remote server or other communication device via a base station. In their mutual communication, communication devices and base stations use licensed radio frequencies that are typically divided into frequency bands and / or time blocks.

  The communication device needs to monitor the control channel operated by the base station in order to be able to communicate via the base station. One of these physical control channels, the so-called physical downlink control channel (PDCCH), carries control information that schedules downlink and uplink resources to individual communication devices. The physical downlink control channel (PDCCH) is transmitted over one or several consecutive control channel element (CCE) aggregations. Scheduling is achieved by the serving base station transmitting downlink control information (DCI) over the PDCCH to each communication device that is scheduling resources in the current scheduling round. Downlink data scheduled in this way is transmitted through a so-called physical downlink shared channel (PDSCH) using resources allocated by DCI. PDSCH resources associated with PDCCH control information (DCI) are generally provided in the same subframe using different frequencies.

  The common control transmission includes, for example, a broadcasted master information block (MIB) and system information block (SIB), a random access response (RAR) message, and paging.

  In order to communicate with the network, the UE must obtain system information. The system information includes configuration information about the network and the serving cell. Since this information is common to all users of the cell, it is broadcast to all UEs in the cell coverage area. The system information is grouped into a message called a master information block (MIB) and a plurality of messages called system information blocks (SIB). The MIB is the most essential system information required by the UE to obtain other information from the cell: system bandwidth, system frame number (SFN), and physical hybrid automatic repeat request (HARQ) indicator. Channel (PHICH) configuration. The MIB is carried on a broadcast channel (BCH) mapped to a physical broadcast channel (PBCH). This is transmitted using a fixed coded modulation scheme and can be decoded after the initial cell search procedure. MIB uses a fixed schedule with a periodicity of 40 ms and a repetition that takes place within 40 ms. The UE can then use the information obtained from the MIB to decode a control format indicator (CFI) that indicates the length of the PDCCH. This makes it possible to decode the PDCCH. The presence of a DCI message scrambled using the System Information Radio Network Temporary Identifier (SI-RNTI) in the PDCCH indicates that the SIB is being carried in the same subframe.

  The SIB is transmitted on the logical channel of the broadcast control channel (BCCH). In general, BCCH messages are carried on the downlink shared channel (DL-SCH) and transmitted on the PDSCH at periodic intervals. The format and resource allocation of the PDSCH transmission is indicated by the DCI message on the PDCCH. LTE / LTE-A defines different SIBs according to the type of system information carried by each SIB. For example, SIB1 includes cell access information including cell identification information, and can indicate whether the UE can camp on the eNB. SIB1 also includes cell selection information (or cell selection parameters). In addition, SIB1 includes scheduling information for other SIBs. Not all SIBs need to be present. Like multiple MIBs, multiple SIBs are broadcast repeatedly. In general, lower SIBs are more time critical and are transmitted more frequently compared to higher SIBs. While SIB1 is transmitted every 80 ms, the transmission periods of a plurality of higher-order SIBs are flexible and may be different for different networks. A plurality of SIBs other than SIB1 are carried in a system information (SI) message. The mapping of multiple SIBs to SI messages includes scheduling information included in SIB type 1 with some limitations, including that only SIBs with the same scheduling requirements (periodicity) can be mapped to the same SI message. Is configured flexibly.

  After the system information of the cell is obtained, the UE can attempt to establish an initial connection by sending a short message on the random access channel. First, the message itself is only very short and contains only a 5-bit random number in order to minimize the possibility that several devices will attempt to send the message simultaneously, resulting in a network access collision. . In addition, the network provides many random access slots per second to randomize access requests over time. When the network picks up the random access request, it assigns a cell-wireless network temporary identifier (C-RNTI) to the mobile and responds to this message with a random access response message. In addition, this message includes an initial uplink bandwidth grant, ie a set of resource blocks of a shared uplink channel that the UE can use in the uplink direction. These resources are then used to send an RRC connection request message that encapsulates the initial attach request.

  The main purpose of the paging message is to page UEs in RRC_IDLE mode in preparation for mobile incoming calls. The paging message can also be used to inform UEs that are in RRC_CONNECTED mode as well as RRC_IDLE mode that system information has changed or that an ETWS notification has been posted to SIB10 or SIB11.

  Recent developments in telecommunications have seen a significant increase in the use of machine-type communication (MTC) UEs, which are network-connected devices that are configured to communicate and operate without human assistance. Examples of such devices include smart meters. The smart meter can be configured to take measurements and relay these measurements to other devices over a telecommunications network. Machine type communication devices are also known as machine-to-machine (M2M) communication devices.

  An MTC device connects to a network whenever it has data to send to or receive from a remote “machine” (eg, server) or user. MTC devices use communication protocols and standards that are optimized for mobile phones or similar user equipment. On the other hand, once deployed, the MTC device typically operates without the need for human management or interaction and follows software instructions stored in internal memory. The MTC device may remain stationary and / or inactive for long periods of time. Specific network requirements to support MTC devices are negotiated in the 3GPP TS22.368 standard. This content is incorporated herein by reference.

  For the Release 13 (Rel-13) version of the standard for MTC devices, support for 1.4 MHz reduced bandwidth in the downlink and uplink is envisioned. Thus, some MTC devices (also referred to as “reduced bandwidth MTC devices”) support only a limited bandwidth (typically 1.4 MHz) compared to the total LTE bandwidth and / or more May have fewer / simplified components. This allows such “reduced bandwidth” MTC devices to be made more economically compared to MTC devices that support greater bandwidth and / or have more complex components. .

  Furthermore, lack of network coverage (eg, when deployed indoors), in combination with the often limited functionality of MTC devices, can result in a reduction in the data rate that such MTC devices have. There is therefore a risk that some messages or channels will not be received by the MTC device. To mitigate this risk, increase the coverage of the PDCCH (or enhanced PDCCH in Rel-13 (“EPDCCH”)) (eg, corresponding to 20 dB for frequency division duplex (FDD) transmission), It has been proposed to support such MTC devices. In order to facilitate such coverage extension, each MTC device has an amount of coverage (eg, 5 dB) required to allow its serving base station to properly adjust its control signaling. / 10 dB / 15 dB / 20 dB coverage extension) to this base station.

  On the other hand, ideally, physical layer control signaling ((E) PDCCH, PUCCH, etc.) and higher layer common control information (eg, SIB, random access response (RAR), paging message, etc.) Shows a high level of commonality between the solution and the coverage extended communication device solution.

  3GPP has recently agreed on the LTE physical layer extension of MTC in Rel-13, including agreement on PBCH and unicast transmission. In the case of PBCH, it uses an old mechanism with more iterations. In the case of unicast transmission, PDSCH transmission is scheduled by the “MTC physical downlink control channel” with supported cross-subframe scheduling. However, it is not yet known how to schedule some specific common control transmissions (eg, SIB / RAR / paging common control messages) of the MTC device. There are at least two options, which are described below.

  The first option includes control-less common control transmission. This is the same design as PBCH in which transmission timing, resource allocation (RA), and transmission format (MCS, RV, etc.) are defined in advance for common control information transmission. Furthermore, the transport block size (TBS) / message size is fixed. For example, in the frequency domain, all six RBs at 1.4 MHz are used to carry the SIB, and in the time domain, the periodicity is also predefined. The advantage of this option is that it provides overhead reduction and power consumption reduction at the UE due to the removal of the control transmission. On the other hand, this disadvantage is the lack of eNodeB scheduling flexibility.

  The second option includes EPDCCH common search space (CSS) transmission that defines CSS in EPDCCH that provides dynamic scheduling of common control information for Rel-13 low complexity UEs. The advantage of this option is the flexibility of eNodeB scheduling to achieve efficient system operation. On the other hand, the disadvantage of this is that it increases the control overhead compared to the first option, more specifically, the coverage overhead in coverage extension mode where a significant number of iterations of multiple SIBs are required. is there.

  The present invention seeks to provide systems, devices and methods that at least partially address the above problems.

  In one aspect, the present invention is a communication apparatus of a communication system, wherein system information is transmitted to a communication device by the communication apparatus in a system information block transmitted according to a system information block transmission scheme. The communication apparatus is configured to operate a cell; and at least one system information block; (i) a plurality of different system information block transmission schemes, and each of the plurality of different system information block transmission schemes is different; According to which of a plurality of different system information block transmission schemes involving transmission of system information blocks of each size, and (ii) the at least one system information block is extended And (iii) at least Means for including control information indicating whether or not two further system information blocks are transmitted after said at least one system information block; and according to said system information block transmission scheme; Means for transmitting the system information block to the communication device in the cell.

  In one aspect, the present invention is a communication apparatus of a communication system, wherein system information is transmitted to a communication device by the communication apparatus in a system information block transmitted according to a system information block transmission scheme. The communication apparatus comprises means for operating a cell; the communication in the cell according to any of a plurality of system information block transmission schemes, each involving transmission of the system information block of a different size Means for transmitting the system information block to a device.

  In one aspect, the present invention is a communication device of a communication system, in which system information is transmitted to the communication device by a communication apparatus in a system information block transmitted according to a system information block transmission scheme. The communication device communicates with the communication device in a cell operated by the communication device, and the communication device receives (i) a plurality of different system information block transmission schemes, and the plurality of different system information blocks. Each of the transmission schemes includes a transmission of the system information blocks of different sizes, according to which of a plurality of different system information block transmission schemes, (ii) at least the Is one system information block extended? And (iii) at least one configured to include control information indicating whether at least one further system information block is transmitted after said at least one system information block and at least one of Means for communicating, operable to receive one system information block; and means for obtaining the system information from one or more system information blocks based on the control information. .

  In one aspect, the present invention is a communication device of a communication system, in which system information is transmitted to the communication device by a communication apparatus in a system information block transmitted according to a system information block transmission scheme. The communication device communicates with the communication device in a cell operated by the communication device, and the system transmits a plurality of system information blocks each with transmission of the system information blocks of different sizes from the communication device. Means for communicating, operable to receive the system information block according to any of the schemes; and decoding one or more system information blocks according to the first of the system information transmission schemes If the system information block is unsuccessful, Means for obtaining the system information from the one or more system information blocks by attempting to decode the one or more system information blocks according to another of the schemes; is there.

  In one aspect, the present invention is a method executed by a communication device of a communication system, wherein the system information is transmitted by the communication device in a system information block transmitted according to a system information block transmission scheme. Transmitted to a communication device, the method comprising: operating a cell; and at least one system information block comprising: (i) a plurality of different system information block transmission schemes, wherein the plurality of different system information block transmission schemes; And (ii) the at least one system information, each according to one of a plurality of different system information block transmission schemes, each involving transmission of a system information block of a different size Whether the block is expanded, iii) configuring at least one further system information block to include control information indicating whether at least one of the at least one system information block is transmitted after the at least one system information block; Transmitting the system information block to a communication device in the cell according to a block transmission scheme.

  In one aspect, the present invention is a method executed by a communication device of a communication system, wherein the system information is transmitted by the communication device in a system information block transmitted according to a system information block transmission scheme. Transmitted to a communication device, the method operating the cell; and according to any of a plurality of system information block transmission schemes, each involving transmission of the system information block of a different respective size Transmitting the system information block to the communication device within.

  In one aspect, the present invention is a method executed by a communication device of a communication system, wherein the system information is transmitted by a communication device in a system information block transmitted according to a system information block transmission scheme. Transmitted to a communication device, the communication device communicates with the communication device in a cell operated by the communication device, and (i) a plurality of different system information block transmission schemes, Each of the different system information block transmission schemes, according to which of the plurality of different system information block transmission schemes is accompanied by transmission of the system information block of different respective sizes, (Ii) the at least one system information Control information indicating whether the lock is extended and (iii) whether at least one further system information block is transmitted after the at least one system information block. Communicating, at least one system information block configured to be operable to receive; obtaining the system information from one or more system information blocks based on the control information; A method comprising:

  In one aspect, the present invention is a method executed by a communication device of a communication system, wherein the system information is transmitted by a communication device in a system information block transmitted according to a system information block transmission scheme. Transmitted to a communication device, the method communicates with the communication device in a cell operated by the communication device, and includes a plurality of transmissions of the system information blocks of different sizes, each from the communication device. One or more systems operable to receive the system information block according to any one of the system information block transmission schemes; and one or more systems according to the first one of the system information transmission schemes Attempts to decode the information block and if unsuccessful, the system Obtaining the system information from the one or more system information blocks by attempting to decode the one or more system information blocks according to another of the information block transmission schemes; Is the method.

  Aspects of the present invention may be adapted to program a programmable processor to perform the corresponding systems, methods, and methods as described in the aspects and possible forms set forth above or in the claims. And / or a computer-readable storage medium having stored thereon instructions operable to program a computer suitably configured to provide the apparatus described in any claim. To various computer program products.

  Each feature disclosed in this specification (including the claims) and / or shown in the drawings is independent of (or in combination with) any other features disclosed and / or illustrated. ) May be incorporated into the present invention. In particular, but not by way of limitation, the features of any of the claims subordinate to a particular independent claim may be incorporated into the independent claim in any combination or individually.

  Exemplary embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

1 is a diagram schematically illustrating a telecommunications system to which an embodiment of the present invention can be applied. It is a block diagram which shows the main components of the communication device shown in FIG. It is a block diagram which shows the main components of the base station shown in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC-specific common control signaling is provided in the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG. FIG. 2 illustrates an exemplary method in which MTC specific common control signaling may be provided to the system illustrated in FIG.

<Outline>
FIG. 1 shows that user equipment 3 (communication devices such as mobile telephone 3-1 and MTC device 3-2) and / or each other via E-UTRAN base station 5 (denoted “eNB”) and core network 7. 1 schematically shows a mobile (cellular) telecommunications system 1 that can communicate with other communication nodes. As will be appreciated by those skilled in the art, FIG. 1 shows one mobile telephone 3-1, one MTC device 3-2, and one base station 5 for illustrative purposes. When implemented, the system typically includes other base stations and communication devices.

  The base station 5 is connected to the core network 7 via the S1 interface. The core network 7 includes, among other things, gateways for connecting to other networks such as the Internet and / or servers hosted outside the core network 7 and communication devices 3 (e.g. mobile phones and A mobility management entity (MME) that tracks the progress of the location of the MTC device) and subscription related information (eg, information identifying which communication device 3 is configured as a machine type communication device), and And a home subscriber server (HSS) that stores control parameters specific to the communication device 3.

  The base station 5 is configured to provide a plurality of control channels including, for example, a physical downlink control channel (PDCCH) and a physical uplink control channel (PUCCH). The PDCCH is used by the base station 5 to allocate resources to the communication device 3 (usually by sending UE specific DCI to each communication device scheduled in the current scheduling round). The PUCCH is used by the communication device 3 to transmit UE specific UCI (eg, appropriate HARQ Ack / Nack corresponding to downlink data received using resources allocated by DCI) to the base station. .

  Each communication device 3 may be classified into one or more of the UE categories. The first category of UEs includes communication devices that only support previous releases of the LTE standard (eg, Rel-8, Rel-9, Rel-10, Rel-11, and / or Rel-12). Such a group of communication devices is commonly referred to as an old UE (assuming base station 5 is operating according to LTE standard Rel-13). The second category of UEs includes reduced bandwidth UEs (eg, Rel-13 MTC devices that can only use 1.4 MHz bandwidth). These UEs cannot communicate over the entire bandwidth available in the base station 5 cell. A third category of UEs includes coverage enhanced UEs (eg, some MTC devices). These UEs require some specific base station functions to be simplified and / or relaxed (although such coverage enhanced UEs may support other functions as usual).

  Advantageously, in order to support a reduced bandwidth MTC device (but not limited to use with this device), the telecommunications system will allow the amount of system information transmitted and / or the amount of system information to be transmitted. A common control transmission scheme without enhanced control that can be flexibly changed according to requirements without significantly increasing signaling overhead to inform one or more UEs of the number of repetitions is used.

  Specifically, a common control transmission scheme without extended control has the potential to allow a relatively small amount or a relatively large amount of system information to be transmitted in an optimal manner, with a relatively small impact. Provides the flexibility to further extend the system (eg, for compatibility with future releases of the standard), allowing transmission of larger amounts of system information in the future.

  Next, a plurality of specific embodiments of the common control transmission method without extended control will be summarized as an example.

  In one exemplary embodiment, for example, a common control transmission scheme without extended control may use one of a plurality of different predetermined TBS / message sizes and / or corresponding scheduling using spare bits of the MIB. Indicates the method (number of repetitions). Advantageously, the number of spare bits required is minimized (eg, 2 to represent 4 possible different schemes). This is because transmission parameters such as modulation scheme or coding rate can be fixed and can be implicitly dependent on TBS / message size and / or repetition rate.

  In a variation of the above exemplary embodiment, the UE is not explicitly informed which of the predetermined TBS and scheduling scheme is used, but instead performs blind decoding, Detect which message transmission format is used. Advantageously, this will incur the resources required to perform blind decoding, but will minimize the changes to the current system elements required to implement the proposal. In particular, the impact and overhead on the signaling configuration is minimized.

  In another exemplary embodiment, for example, a common control transmission scheme without extended control is provided with extensions to one or more MTC-SIBs using one or more bits in the MTC-SIB. Indicates that This has the advantage that backward / forward compatibility is improved. For example, multiple MTC UEs in Rel-13 need only read the Rel-13 portion of the SI regardless of the availability of the extension, while UEs in later releases may use the availability bit And the expanded portion can be read based on the corresponding scheduling information. This extended portion is preconfigured in this example (eg, according to the standard specification of the corresponding release), but can be provided dynamically in the MTC-SIB.

  In yet another exemplary embodiment, for example, a common control transmission scheme without extended control uses one or more bits in the MTC-SIB to transmit one or more additional MTC-SIBs. Indicates that

  In yet another exemplary embodiment, the common control transmission scheme without extended control is a dedicated “scheduling” MTC-SIB or “master” that includes information indicating the presence of any other MTC-SIB being transmitted. MTC-SIB is provided.

  In any of the foregoing embodiments, one or more additional bits are used to (additional) scheduling information for one or more future SIBs (eg, periodicity, offset, repetition count / window, (Information of one or more resource allocations, transmission formats, etc.) (either in the form of specific scheduling information or in the form of identification information in one of a plurality of preconfigured schemes) It will be understood that it can be done. However, the dynamic provision of such (additional) scheduling information is completely optional and the scheduling information can instead be preconfigured.

  Thus, in effect, the exemplary embodiment above provides possible advantages over both the uncontrolled common control transmission option and the EPDCCH common search space (CSS) transmission option mentioned in the background section. It offers an advantageous solution and opens up the possibility to expand the SIB size and improve scheduling flexibility in the future.

<Communication device>
FIG. 2 is a block diagram showing main components of the communication device 3 shown in FIG. The communication device 3 may be an MTC device or a mobile (or “cellular”) telephone configured as a machine type communication device. The communication device 3 includes a transceiver circuit 31 that is operable to transmit and receive signals to and from the base station 5 via at least one antenna 33. Typically, the communication device 3 also includes a user interface 35 that allows a user to exchange information with the communication device 3, but this user interface 35 may be omitted for some MTC devices.

  The operation of the transceiver circuit 31 is controlled by the controller 37 according to software stored in the memory 39. This software includes, among other things, an operating system 41, a communication control module 43, an MTC module 45, and a system information module 47.

  The communication control module 43 controls communication between the communication device 3 (via the base station 5) and the base station 5 and / or other communication nodes. As shown in FIG. 2, the communication control module 43 includes, among other things, an EPDCCH module unit (for managing communication through an extended physical downlink control channel) and a PDSCH module unit (communication through a physical downlink shared channel). And a PUCCH module part (for managing communication through a physical uplink control channel). The MTC module 45 is operable to perform machine type communication tasks. For example, the MTC module 45 may receive data (eg, periodically) from a remote server (via the transceiver circuit 31) through resources allocated to the MTC device 3 by the base station 5. The MTC module 45 may collect data to send (eg, periodically and / or upon detection of a trigger) to a remote server (via the transceiver circuit 31).

  The system information module 47 is a system received in multiple system information blocks via the antenna 33 and the transceiver circuit 31 in accordance with a common control transmission scheme without extended control of any of the embodiments described herein. Responsible for locating, identifying and decrypting information.

<Base station>
FIG. 3 is a block diagram showing main components of the base station 5 shown in FIG. Base station 5 comprises an E-UTRAN base station (eNB) comprising a transceiver circuit 51 operable to send and receive signals to and from communication device 3 via one or more antennas 53. The base station 5 is also operable to send and receive signals to and from the core network 7 via an appropriate core network interface 55 (such as an S1 interface). The operation of the transceiver circuit 51 is controlled by the controller 57 according to software stored in the memory 59.

  This software includes, among other things, an operating system 61, a communication control module 63, a UE category determination module 65, and a system information module 67.

  The communication control module 63 controls communication with the communication device 3 (including any MTC device). The communication control module 63 is also responsible for scheduling resources used by the communication device 3 served by this base station 5. As shown in FIG. 3, the communication control module 63 includes, among other things, an EPDCCH module unit (for managing communication through an extended physical downlink control channel) and a PDSCH module unit (communication through a physical downlink shared channel). And a PUCCH module part (for managing communication through a physical uplink control channel).

  The UE category determination module 65 determines the category of the communication device 3 served by the base station 5 based on, for example, information acquired from the communication device 3 and / or another network node (eg, HSS). Where appropriate, the UE category determination module 65 provides information identifying the category of each served communication device to other modules, eg, the communication control module 63, so that these other modules can identify themselves. So that the behavior of the can be adjusted accordingly.

  The system information module 67 is a system in a plurality of system information blocks via the antenna 53 and the transceiver circuit 51 according to a common control transmission scheme without extended control of any of the exemplary embodiments described herein. Responsible for managing the transmission of information.

  In the above description, the communication device 3 and the base station 5 have been described as having a plurality of separate modules for easy understanding. These modules may be provided in this way for some specific applications where, for example, an existing system has been modified to implement the invention, but other applications such as the features of the present invention In a system designed in consideration of these, these modules may be incorporated into the entire operating system or code, so these modules may not be distinguished as separate entities.

  In the following, various ways in which common control signaling can be provided in an LTE system are described.

<System Information for Rel-13 Low Complexity UE>
As described above, a plurality of requirements are determined for the Rel-13 version of the standard for MTC devices compared to older systems. For example, the system information must be repeated a sufficient number of times to ensure a 15 dB coverage improvement that allows multiple UEs to correctly receive multiple SIBs. However, a larger TB size requires more iterations. For this reason, it is desirable to limit any increase in size and also provide scheduling flexibility. On the other hand, this may limit further enhancements possible in future releases.

  These issues may be overcome or ameliorated by using one or more of the following common control transmission examples 1-4 without extended control described below. This concept offers possible advantages over both uncontrolled common control transmission options and EPDCCH common search space (CSS) transmission options, and the potential to expand SIB size and improve scheduling flexibility in the future. It is also based on the idea of finding a common control transmission without improved control.

Example 1
<Operation-First Example>
A first exemplary method in which MTC common control transmission may be provided in the system shown in FIG. 1 is shown in FIG.

As can be seen in FIG. 4, in step S410, the MIB is transmitted to the UE 3 by the base station 5, and a plurality of bits in the MIB are used to indicate one of a plurality of predetermined system information transmission schemes. . Each system information transmission method represents a different configuration having a different transport block size (TBS), a corresponding scheduling method, and the number of repetitions. In particular, four combinations of two bits are defined as follows:
-"00" indicates a 152 bit, time domain repeat N1 TBS;
-"01" indicates 256 bits, time domain repetition N2 TBS (N2>N1);
-"10" indicates 328 bits, TBS of time domain repetition N3 (N3>N2);and-"11" indicates 504 bits, TBS of time domain repetition N4 (N4> N3).

  The predefined values N1, N2, N3 and N4 are the number of iterations required to achieve the same coverage target value for each TBS.

  Thus, in this example, the TBS / message size is variable and is signaled in the MIB. Similarly, repetition in the time domain is also variable and depends on the TBS size reaching the extended coverage target value. On the other hand, resource allocation (RA) is fixed to six resource blocks (RB) in the frequency domain, and modulation is fixed to QPSK. Furthermore, the coding rate is implicitly dependent on the TBS size. Therefore, there is no need to transmit information indicating resource allocation, information indicating modulation, or information indicating coding rate.

  In step S411, the UE 3 identifies which one of a plurality of predetermined system information transmission schemes is used for SIB transmission from a plurality of bits corresponding to the MIB, and thus which default transport block size (TBS), identifying the corresponding scheduling scheme and number of iterations being used.

  In step S 412-0, the first SIB is transmitted by the base station 5 according to the system information transmission method identified by the base station 5 in the MIB. This procedure is then repeated (as necessary) according to the system information transmission scheme identified in the MIB, as indicated by steps S412-1 and S412-2 (for simplicity, two iterations are performed). As shown, any number is possible including no repetition). Next, after the number of repetitions of the identified scheme, in step S414, the UE 3 receives a plurality of received SIBs based on the system information transmission scheme identified by the UE from the MIB in order to derive system information. Decrypt the soft join. In this example, soft combining decoding is performed after multiple SIB transmission iterations, but it will be appreciated that soft combining itself is performed cumulatively after every SIB retransmission.

  In this particular example, two bits in the MIB are used, but it will be understood that fewer bits or more may be used depending on the number of predefined TBS sizes. Will.

  In one variation of this example shown in FIG. 5, the communication device 3 (eg, MTC device 3-2) is not informed by the base station 5 of the system information transmission scheme used, so the TBS and the number of repetitions are It does not know itself, but instead performs “blind decoding” to determine which TBS is being used.

  Specifically, in this variant, the base station 5 simply transmits the first SIB according to an unidentified system information transmission scheme. This procedure is then repeated for the number of iterations associated with the system information transmission scheme (eg, steps S512-1, S512-2, S512-3, S512-4). In step S514-0, according to the number of repetitions associated with the system information transmission scheme with the minimum TBS (and thus the minimum number of repetitions), UE3 determines from the first repetition to the last repetition based on the system information transmission scheme. Attempts to decode a plurality of SIBs received so far, using all of the repeated soft combinations. If the decoding is not successful, in step S514-1, according to the total number of repetitions associated with the system information transmission scheme with the next smallest TBS (and hence the next smallest number of repetitions), UE3 Based on the information transmission scheme, attempts are made to decode a plurality of SIBs received so far using the soft combination of all iterations from the first iteration to the last iteration. This procedure continues until successful decoding is achieved. In this example, the soft combining attempted decoding is performed after multiple SIB transmission iterations, and then, after unsuccessful, after another SIB transmission repetition number, the soft combining itself is This is done cumulatively after every SIB retransmission.

  This procedure is described in more detail below with respect to the foregoing exemplary TBSs and corresponding scheduling schemes.

(I) For iterations 1 to N1, the communication device 3 attempts a soft combination and decoding of the TB assuming a 152-bit TBS;
(Ii) If (i) fails, between iterations (N1 + 1) to N2, the communication device 3 uses 256 soft combinations of all iterations from 1 to the last iteration (ie, N2). Attempt to decode TB assuming bit TBS;
(Iii) If (ii) fails, between iterations (N2 + 1) to N3, the communication device 3 uses all iterations of soft join from 1 to the last iteration (ie, N3) 328 Attempt to decode TB assuming bit TBS;
(Iv) If (iii) fails, between iterations (N3 + 1) to N4, the communication device 3 uses 504 the soft combination of all iterations from 1 to the last iteration (ie, N4). Attempt to decode TB assuming a bit TBS.

  In any variation of this example, the UE may decode soft combinations of multiple SIBs received so far at any suitable interval (eg, after every iteration or after every other iteration, etc.). Or it will be understood that a decoding attempt may be made.

Example 2
<Operation-second example>
In a second exemplary method in which MTC common control transmission may be provided in the system shown in FIG. 1, one or more dedicated MTC-SIB bits indicate the presence of an extension for one or more MTC-SIBs. It is shown in FIG.

  As can be seen in FIG. 6, each MTC-SIB 402-1 to 402-n is one (or more) indicating that the extension 406 of that MTC-SIB 402 is available (or not available). Bits 404-1 through 404-n can be included. Specifically, in this example, each MTC-SIB is, for example, one of two values such as “1” or “0” indicating whether or not the extension unit 406 of the MTC-SIB 402 is available. Contains a single bit information element (or flag) having one.

  Further, the extension part 406 of the MTC-SIB is, for example, one of two values such as “1” or “0” indicating whether or not the further extension part 410 of the MTC-SIB is available. Contains a single bit information element (or flag) having one. As described above, in the example illustrated in FIG. 6, the MTC-SIB 402-1 includes the bit 404-1 having a value of “1” indicating that the extension unit 406 of the SIB 402-1 is available. Furthermore, the extension 406 of the SIB 402-1 includes a bit 408 having a value of “1” indicating that a further extension 410 of the SIB 402-1 is available. On the other hand, MTC-SIB 402-n includes bit 404-n having a value of “0” indicating that an extension of SIB 402-n is not available. Thus, this bit effectively functions as a pointer that indicates the availability of the extension (or further extension).

  In practice, this example is a standard for MTC devices by setting the bit to “0” and allowing future releases to set the bit to “1” and defining an extension. It may be implemented for the Rel-13 version of the standard. For example, the extension part may be a message of the extension part of MTC-SIB # n (TBS) and its scheduling method, resource allocation (RA) (including time position and spectrum position, and number of repetitions), or transmission format (MCS, RV, etc.) ) Can be specified.

  Alternatively, as shown in FIG. 7, any one of the plurality of MTC-SIBs 502 may have general availability of the system information extension 506 of any of the plurality of MTC-SIBs 502. Can be included. That is, an arbitrary one of the plurality of MTC-SIBs 502 has, for example, two values such as “1” and “0” indicating whether or not the system information expansion unit 506 is available as a whole. Bits 504 (or flags) having one of them can be included. Further, the expanded system information 506 itself can be expressed as one of two values, such as “1” or “0”, respectively, indicating whether or not further extensions of system information are generally available. Bit 508 can be included. For example, as illustrated in FIG. 5, the MTC-SIB 502-1 includes a bit 504 having a value of “1” indicating that the extension unit 506 for the system information exists. The extension 506 itself includes a bit 508 having a value of “1” indicating that there is a further extension 510 of system information.

  In practice, this example sets the bit to “0” and allows future releases to set the bit to “1” to allow the specification of the contents of one or more extensions. May be implemented for the Rel-13 version of the standard for MTC devices. For example, one or more extensions may include one or more messages of extension information designated as MTC-SIB-extensions (TBS) and their scheduling schemes, resource allocation (RA) (time position and spectrum position and repetition The transmission format (MCS, RV, etc.).

  Optionally, the corresponding scheduling information of the extension can be indicated.

Example 3
<Operation-Third Example>
A third exemplary method in which MTC common control transmission may be provided in the system shown in FIG. 1 is to indicate one or more bits in one MTC-SIB to indicate the availability of subsequent MTC-SIBs. 8 and 9 that can be used.

As seen in FIG. 8, MTC-SIB _n 602-n may include one or more bits that indicate the availability of MTC-SIB _{n + 1} 602-n + 1. It will be appreciated that multiple MTC-SIBs may optionally also include corresponding scheduling information for the next MTC-SIB.

Referring to FIG. 9, which shows how UE3 can read and interpret the MTC-SIB, in step S902, the UE first uses a method similar to PBCH with a fixed message size and scheduling scheme. , MTC-SIB ₁ 602-1 is read. After decoding MTC-SIB ₁ 602-1, UE3 knows that another MTC-SIB 602-2, shown as MTC-SIB ₂ , is present. Therefore, in step S904, UE3 reads the _MTC-SIB 2 602-2, after decoding this, UE3, since there is a bit 604-2 having a value of "1", MTC-SIB ₃ Determine that there is yet another MTC-SIB, shown as 602-3. Therefore, in step S906, UE3 reads MTC-SIB ₃ 602-3 and determines that there is no more MTC-SIB, that is, bit 604-3 has a value of “0”.

MTC-SIB _n and its scheduled MTC-SIB _{n + 1} can be in the same release or in adjacent releases.

  FIGS. 10a and 10b may indicate where and how one or more bits are added and how to extend the MTC-SIB or subsequent MTC-SIB according to the second and third examples. Is shown. For example, as shown in FIG. 10a, the IE can be included in the MTC-SIB message. Alternatively, as shown in FIG. 10b, information can be added to the end of the TB in the physical layer.

Example 4
<Operation-fourth example>
A fourth exemplary method by which MTC common control transmission may be provided in the system shown in FIG. 1 is illustrated in FIG. 11a, where one MTC-SIB contains information indicating the availability of all other MTC-SIBs, and others. The scheduling information for all MTC-SIBs is also shown in FIG.

Specifically, FIGS. 11a and 11b provide two examples of how such information can be included in the MTC-SIB. As seen in FIG. 11a, information identifying the presence or absence of other MTC-SIBs is provided as a bitmap. For example, the bitmap shows that the first bit (“b0”) indicates the availability of MTC-SIB ₁ , the second bit (“b1”) indicates the availability of MTC-SIB ₂ , etc. An N-bit (eg, 20 bits) bitmap corresponding to N (eg, 20) MTC-SIBs may be included. Alternatively, this information can be provided as a list, as shown in FIG. 11b. In this list, the first entry in the list indicates the availability of MTC-SIB ₁ and, optionally, what is the corresponding scheduling information if available, and the second in the list The entry indicates the availability of MTC-SIB ₂ and, optionally, what is the corresponding scheduling information if it is available.

As seen in FIG. 11b, scheduling information for all subsequent MTC-SIBs may be sent in a single evolved MTC-SIB, eg, MTC-SIB ₁ in another example.

<Changes and alternatives>
Detailed exemplary embodiments have been described above. As those skilled in the art will appreciate, a number of changes and alternatives may be made to the exemplary embodiments described above, while still benefiting from the invention embodied above.

  It will be appreciated that the inclusion of scheduling bits is completely optional so that the message size can be kept to a minimum. Scheduling can be a default if not included. The scheduling information may include one or more of periodicity, offset, number of repetitions / window, resource allocation, and transmission format.

  It is understood that these examples described above are not incompatible, and any of these examples may be combined in the same system, in a single cell, and / or in neighboring cells. Will.

  Although the communication system has been described with reference to a base station operating as an E-UTRAN base station (eNB), the same principles provide elements of base stations, femto base stations, base station functions that operate as macro base stations or pico base stations It will be appreciated that the invention may also apply to relay nodes, home base stations (HeNBs) or other such communication nodes.

  In the above exemplary embodiment, an LTE telecommunications system has been described. As will be appreciated by those skilled in the art, the techniques described in this application can be used in other communication systems, including previous 3GPP type systems. Other communication nodes or devices may include user devices such as personal digital assistants, laptop computers, web browsers, and the like.

  In the exemplary embodiment described above, the base station and the communication device each comprise a transceiver circuit portion. Usually, this circuit part is formed by a dedicated hardware circuit. However, in some exemplary embodiments, a portion of the transceiver circuitry may be implemented as software executed by a corresponding controller.

  In the exemplary embodiment above, multiple software modules have been described. As will be appreciated by those skilled in the art, the software modules can be provided in compiled or uncompiled form and supplied to the base station or user device as a signal or in a recording medium via a computer network. May be. Further, the functions performed by part or all of this software may be performed using one or more dedicated hardware circuits.

  In the above exemplary embodiments, machine type communication devices and mobile phones have been described. However, it will be appreciated that the mobile telephone (and similar user equipment) may also be configured to operate as a machine type communication device. For example, the mobile telephone 3-1 may include (and / or provide the functionality of) this module.

Examples of MTC Applications It will be appreciated that each communication device may support one or more MTC applications. Some examples of MTC applications are listed in the following table (Source: 3GPP TS 22.368, Appendix B). This list is not exhaustive and is intended to show the range of uses for machine type communication.

  Although a common control transmission scheme without extended control has been disclosed with particular reference to MTC devices that are particularly advantageous, it will be understood that any type of user equipment may have advantages.

  Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

  This application claims priority based on British Patent Application No. 1501618.1 filed Jan. 30, 2015, the entire disclosure of which is incorporated herein.

Claims (4)

A user equipment communicating with a base station,
Means for receiving a master information block (MIB) including first information in a broadcast channel (BCH);
Means for determining a transport block size (TBS) for a system information block (SIB) and the number of repetitions of the SIB based on the first information;
Means for receiving the SIB based on the first information;
The SIB indicates TBS information for other system information,
User device. A method performed by a user equipment communicating with a base station, comprising:
Receiving a master information block (MIB) including first information on a broadcast channel (BCH);
Determining a transport block size (TBS) for a system information block (SIB) and the number of repetitions of the SIB based on the first information;
Receiving the SIB based on the first information;
Wherein the SIB indicates TBS information for other system information. A base station that communicates with user equipment,
Means for transmitting in a broadcast channel (BCH) a master information block (MIB) including a transport information block size (TBS) of a system information block (SIB) and first information indicating the number of repetitions of the SIB;
Means for transmitting the SIB based on the TBS and the number of repetitions;
With
The SIB is a base station indicating TBS information for other system information. A method performed by a base station communicating with a user equipment comprising:
In a broadcast channel (BCH), transmitting a master information block (MIB) including first information indicating a transport block size (TBS) of a system information block (SIB) and the number of repetitions of the SIB;
Transmitting the SIB based on the TBS and the number of repetitions;
Wherein the SIB indicates TBS information for other system information.

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